Hydrochloric Acid → 4-[4-(cyclopropylsulfonyl)phenyl]-5-(tetrahydro-2H-pyran-4-yl)pent-1-en-3-one

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Reaction Steps

To a solution of 2-[4-(cyclopropylsulfonyl)phenyl]-N-methoxy-N-methyl-3-(tetrahydro-2H-pyran-4-yl)propanamide (10.2 g) in tetrahydrofuran (100 mL) was added dropwise vinylmagnesium bromide (1.0M tetrahydrofuran solution, 73 mL) under ice-cooling. The reaction mixture was stirred overnight at room temperature, 1M hydrochloric acid (80 mL) was added and the mixture was further stirred for 30 min. The reaction mixture was extracted with ethyl acetate, and the ethyl acetate layer was washed with saturated aqueous sodium hydrogen carbonate and saturated brine, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and the title compound (4.25 g, yield 46%) was obtained as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:2, volume ratio). melting point 92-93° C. MS: 349 (MH+).

Provenance & Evidence